Multi-type air conditioner and method of controlling the same

ABSTRACT

A multi type air conditioner is provided that may include a plurality of indoor devices, each comprising an indoor heat exchanger, and a plurality of outdoor devices connected to the plurality of indoor devices, each comprising an outdoor heat exchanger. When a defrosting operation condition is satisfied during a heating operation, the plurality of outdoor devices may successively perform a defrosting operation.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2011-0037773, filed in Korea on Apr. 22, 2011, which is hereby incorporated by reference in its entirety.

BACKGROUND

1. Field

A multi-type air conditioner and a method of controlling a multi-type air conditioner are disclosed herein.

2. Background

Multi-type air conditioners are known. However, they suffer from various disadvantages.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements, and wherein:

FIG. 1 is a block diagram of a multi-type air conditioner according to an embodiment;

FIG. 2 is a circuit diagram of a refrigerant cycle of the multi-type air conditioner of FIG. 1;

FIG. 3 is a circuit diagram of a refrigerant flow when the multi-type air conditioner of FIG. 1 performs a cooling operation;

FIG. 4 is a flowchart of a method of controlling a multi-type air conditioner according to an embodiment;

FIGS. 5 to 8 are block diagrams illustrating successive defrosting operations of a plurality of outdoor devices; and

FIGS. 9 and 10 are circuit diagrams of a refrigerant flow when a specific outdoor device performs a defrosting operation, FIG. 9 illustrating a refrigerant flow when a fourth outdoor device performs a defrosting operation, and FIG. 10 illustrating a refrigerant flow when a first outdoor device performs a defrosting operation.

DETAILED DESCRIPTION

Hereinafter, embodiments will be described with reference to the accompanying drawings. Where possible, like reference numerals have been used to indicate like elements. Also, in the description of embodiments, detailed description of well-known related structures or functions has been omitted.

In general, an air conditioner is an apparatus that cools/heats an indoor space or purifies indoor air using a refrigerant cycle including a compressor, a condenser, an expansion mechanism, and an evaporator to provide a comfortable indoor environment for users. Air conditioners may be classified as an air conditioner in which a single indoor device is connected to a single outdoor device or a multi-type air conditioner in which a plurality of indoor devices is connected to a single outdoor device to provide the effect of a plurality of air conditioners.

The multi-type air conditioner may include a plurality of indoor devices and a plurality of outdoor devices. Each of the plurality of outdoor devices may include an outdoor heat exchanger. Each of the outdoor heat exchangers may be divided into an upper heat exchanger part and a lower heat exchanger part on the basis of a flow of refrigerant. Thus, refrigerant may independently flow into the upper and lower heat exchanger parts.

Generally, in the multi-type air conditioner, when the heating operation is continuously performed, frost may develop on the outdoor heat exchanger. Thus, a defrosting operation should be performed. When the defrosting operation is performed, the frost on the upper heat exchanger part of each of the plurality of outdoor heat exchangers may be removed first. Then, when the frost on the upper heat exchanger part is completely removed, the frost on the lower heat exchanger part may be removed. When the defrosting operation is performed, a high-temperature, high-pressure refrigerant discharged from a compression device may be bypassed to flow into the heat exchanger part in which the defrosting operation has been performed.

In the case of the above-described multi-type air conditioner, a portion (about approximately 50% of the whole outdoor heat exchanger) of the heat exchanger part in each of the outdoor heat exchangers of the whole outdoor device performs the defrosting operation, and the remaining portion (about approximately 50% of the whole outdoor heat exchanger) performs a heating operation. Thus, heating efficiency may be deteriorated.

Also, because the frost on the upper heat exchanger part may be completely removed, and then, the frost on the lower heat exchanger part removed, the frost on a boundary between the upper heat exchanger part and the lower heat exchanger part may not be smoothly removed. Thus, frost may remain on the boundary.

Also, when the defrosting operation is performed, because the refrigerant bypassed to the compression device flows into the outdoor heat exchanger, an amount of refrigerant flowing into the outdoor heat exchanger may be less. Thus, it may take a relatively long time to remove the frost.

FIG. 1 is a block diagram of an air conditioner according to an embodiment. FIG. 2 is a circuit diagram of a refrigerant cycle of the multi-type air conditioner of FIG. 1. For example, FIG. 2 illustrates a refrigerant flow when the multi-type air conditioner of FIG. 1 performs a heating operation.

Referring to FIGS. 1 and 2, the multi-type air conditioner according to this embodiment may include an outdoor device 1, an indoor device 2 connected to the outdoor device 1 through a distributor 3, a controller (not shown) that controls operations of the multi-type air conditioner, and a memory (not shown). The outdoor device 1 may include a plurality of outdoor devices 11, 12, 13, and 14. The indoor device may 2 include a plurality of indoor devices 21, 22, 23, and 24. For convenience of description, although four indoor devices are shown connected to four outdoor devices in this embodiment, the present disclosure is not limited to this number of indoor and outdoor devices. That is, two or more indoor devices may be connected to two or more outdoor devices. Further, the number of indoor device may be greater than the numbers of outdoor devices.

The outdoor device 1 may include a first outdoor device 11, a second outdoor device 12, a third outdoor device 13, and a fourth outdoor device 14. The first outdoor device 11 may have the same configuration as that of each of the second to fourth outdoor devices 12, 13, and 14. Thus, only the configuration of the first outdoor device 11 will be described hereinbelow. The descriptions of the first outdoor device 11 may be equally applied to those of the second to fourth outdoor devices. Also, reference numerals used for explaining the configuration of the first outdoor device 11 may be equally applied to those of the second to fourth outdoor device.

Each of the outdoor devices 11, 12, 13, and 14 may include a compression device 110 that compresses a refrigerant, and outdoor heat exchangers 130, 200, 210, and 220, in which outdoor air is heat-exchanged with the refrigerant. The compression device 110 may include one or more compressors. For example, the compression device 110, which may include a plurality of compressors 111, 112, and 113, will be described as an example. One or more of the plurality of compressors 111, 112, and 113 may be an inverter compressor, such as compressor 111, having a variable capacity, and others may be a constant-speed compressors, such as compressors 112 and 113. The plurality of compressors 111, 112, and 113 may be disposed in parallel. One or more of the plurality of compressors 111, 112, and 113 or all of the plurality of compressors 111, 112, and 113 may be operated according to a capacity of the indoor device.

A discharge side tube of each of the compressors 111, 112, and 113 may include an individual tube 118 and a joint tube 119. That is, the individual tube 118 of each of the compressors 111, 112, and 113 may be jointed to the joint tube 119. The individual tube 118 may include an oil separator 114, 115, or 116 that separates oil from the refrigerant, a temperature sensor 126 that detects a temperature of the compressed refrigerant, and a compression sensor 127 that detects a pressure of the compressed refrigerant.

The joint tube 119 may be connected to a plurality of valves 121 and 122, which may be 4-way valves, that switch a flow of the refrigerant. The plurality of valves 121 and 122 may include a first valve 121 and a second valve 122. The first and second valves 121 and 122 may be disposed in parallel.

Each of the first and second valves 121 and 122 may be connected to the outdoor heat exchanger 130 through first connection tubes 123 and 124, respectively. The first connection tubes 123 and 124 may include a first heat exchanger part connection tube 123 and a second heat exchanger connection tube 124.

Each of the outdoor heat exchangers 130, 200, 210, and 220 may include a plurality of heat exchanger parts. For example, the plurality of heat exchanger parts may include a first heat exchanger part 131 and a second heat exchanger part 132. The first and second heat exchanger parts 131 and 132 may be independent heat exchangers separated from each other, or a single heat exchanger divided into two parts based on refrigerant flow. The first valve 121 may be connected to the first heat exchanger part 131 through the first heat exchanger part connection tube 123, and the second valve 122 may be connected to the second heat exchanger part 132 through the second heat exchanger part connection tube 124. The first and second heat exchanger parts 131 and 132 may be disposed in parallel. Further, the first and second heat exchanger parts 131 and 132 may be horizontally or vertically disposed with respect to each other. The refrigerant may flow into each of the first and second heat exchanger parts 131 and 132, or only one of the first and second heat exchanger parts 131 and 132. The refrigerant may flow into the first heat exchanger part 131 in a direction opposite to that of the refrigerant flowing into the second heat exchanger part 132. That is, the first and second heat exchanger parts 131 and 132 may be independently operated. Moreover, each of the heat exchangers may independently serve as a condenser or an evaporator.

Although each of the outdoor heat exchangers may be divided into the plurality of heat exchanger parts and may include a plurality of valves in this embodiment, the present disclosure is not so limited. For example, a single valve may be connected to the outdoor heat exchanger.

The refrigerant within the outdoor heat exchanger may be heat-exchanged with outdoor air blown by a fan motor assembly 140, which may include an outdoor fan and a fan motor. A plurality of fan motor assemblies may be provided. For example, FIG. 1 illustrates two outdoor fan motor assemblies; however, embodiments are not limited to this number of outdoor fan motor assemblies.

Also, each of the valves 121 and 122 may be connected to an accumulator 135 through the second connection tube 134. Additionally, each of the valves 121 and 122 may be connected to closed tubes 121 a and 122 a.

Each of the outdoor devices 11, 12, and 13, and 14 may further include an outdoor expansion mechanism 150. The outdoor expansion mechanism 150 does not expand a refrigerant when the refrigerant passes through the outdoor heat exchangers 130, 200, 210, and 220, but rather, expands refrigerant which does not pass through the outdoor heat exchangers 130, 200, 210, and 220.

The outdoor expansion mechanism 150 may include a first outdoor expansion valve 151 corresponding to the first heat exchanger part 131 and a second outdoor expansion valve 152 corresponding to the second heat exchanger part 132. The first and second outdoor expansion valves 151 and 152 may be disposed in parallel. That is, the refrigerant expanded by the first outdoor expansion valve 151 may flow into the first heat exchanger part 131, and the refrigerant expanded by the second outdoor expansion valve 152 may flow into the second heat exchanger part 132. Each of the outdoor expansion valves 151 and 152 may be an electronic expansion valve (EEV), for example.

Each of the outdoor devices 11, 12, 13, and 14 may be connected to the distributor 3 through a low pressure gas tube 311 and a low pressure connection tube 312. Also, each of the outdoor devices 11, 12, 13, and 14 may be connected to the distributor 3 through a high pressure tube 321 and a high pressure connection tube 322. Additionally, each of the outdoor devices 11, 12, 13, and 14 may be connected to the distributor 3 through a liquid tube 331 and a liquid connection tube 332.

The low pressure gas tube 311 may be connected to the second connection tube 134 and the low pressure connection tube 312. The high pressure tube 321 may be connected to the joint tube 119 and the high pressure connection tube 322, which may be disposed downflow from the valves 121 and 122. The liquid tube 331 may be connected to the outdoor expansion mechanism 150 and the liquid connection tube 332.

The distributor 3 may be connected to the plurality of indoor devices 21, 22, 23, and 24 and the outdoor device 1 to control refrigerant flow. The distributor 3 may be connected to each of the indoor devices 21, 22, 23, and 24 through an indoor gas tube 313 and an indoor liquid tube 333.

The distributor 3 may include a low pressure gas pipe 31, a high pressure gas pipe 32, a liquid pipe 33, a low pressure valve 314, and a high pressure valve 324. The low pressure connection tube 312 and the indoor gas tube 313 may be connected to the low pressure gas pipe 31, and the indoor liquid tube 333 and the liquid connection tube 332 may be connected to the liquid pipe 33. The high pressure connection tube 322 and a branch tube 323 connected to the indoor liquid tube 333 may be connected to the high pressure gas pipe 32. The low pressure gas tube 311 may include first valves 315 and 316, the high pressure gas tube 321 may include second valves 325 and 326, and the liquid tube 331 may include third valves 335 and 336.

The indoor gas tube 313 may include the low pressure valve 314, and the high pressure valve 324 may be connected to the branch tube 323. In this embodiment, the low pressure valve 314 and the high pressure valve 324 may be, for example, an EEV, in which an opening degree thereof may be adjusted linearly or in a stepwise fashion.

Each of the indoor devices 21, 22, 23, and 24 may include indoor heat exchangers 211, 221, 231, and 241, indoor fans 212, 222, 232, and 242, and indoor expansion mechanisms 213, 223, 233, and 243. Each of the indoor expansion mechanisms 213, 223, 233, and 243 may be an EEV, for example.

Hereinafter, an operation of a multi-type air conditioner according to an embodiment will be described.

Referring to FIG. 2, when the multi-type air conditioner performs a heating operation, i.e., when one or more indoor devices perform a heating operation (for example, the four indoor devices perform the heating operation in FIG. 1), a high temperature refrigerant discharged from the compression device 110 of the plurality of outdoor devices 11, 12, 13, and 14 may flow toward the indoor device. The low pressure valve 314 may be closed, and the high pressure valve 324 opened. Also, the first valves 315 and 316 disposed in the low pressure gas tube 311 may be closed.

The high-temperature, high-pressure refrigerant discharged from the compression device 110 may flow into the high pressure gas pipe 32 along the high pressure gas tube 321 by adjusting the refrigerant flow through the valves 121 and 122. Because the joint tube 119 communicates with the closed tubes 121 a and 122 a via the valves 121 and 122, the refrigerant does not flow from an end of the closed tubes 121 a and 122 a, and thus, flows along the high pressure gas tube 321.

The refrigerant flowing into the high pressure gas pipe 32 may flow into each of the indoor heat exchangers 211, 221, 231, and 241 through the branch tube 323 and the indoor gas tube 313. Then, the refrigerant may be condensed in the indoor heat exchangers 211, 221, 231, and 241 and pass through the indoor expansion mechanisms 213, 223, 233, and 243, without being expanded, to flow into the liquid pipe 33 through the indoor liquid tube 333. The refrigerant flowing into the liquid pipe 33 may flow along the liquid connection tube 332 and the liquid tube 331. Then, the refrigerant may be expanded by the outdoor expansion mechanism 150 to flow into the outdoor heat exchangers 130, 200, 210, and 220. The refrigerant may be evaporated while passing through the outdoor heat exchangers 130, 200, 210, and 220, and then the refrigerant may pass through each of the valves 121 and 122 to flow into the accumulator 135. A gaseous portion of the refrigerant introduced into the accumulator 135 may be introduced into the compression device 110.

As described above, when the heating operation is continuously performed, frost may occur or form on the outdoor heat exchangers 130, 200, 210, and 220. Thus, a defrosting operation to remove the frost from the outdoor heat exchangers 130, 200, 210, and 220 may be required. The defrosting operation will be described later.

FIG. 3 is a circuit diagram of a refrigerant flow when the multi-type air conditioner performs a cooling operation. Referring to FIG. 3, a cooling operation will be described hereinbelow.

When the multi-type air conditioner performs a cooling operation, i.e., when one or more indoor devices perform a cooling operation (for example, the four indoor devices perform the cooling operation in FIG. 3), a refrigerant discharged from the compression device 130 of the plurality of outdoor devices 11, 12, 13, and 14 may flow toward the outdoor heat exchangers 130, 200, 210, and 220. The high pressure valve 324 may be closed, and the low pressure valve 314 opened. Also, the second valves 325 and 326 disposed in the high pressure gas tube 321 may be closed.

The high-temperature, high-pressure refrigerant discharged from the compression device 110 may flow into each of the outdoor heat exchangers 130, 200, 210, and 220 along the first connection tubes 123 and 124 by adjusting the refrigerant flow through the valves 121 and 122. Then, the refrigerant may be condensed while passing through the outdoor heat exchangers 130, 200, 210, and 220 to pass through the outdoor expansion mechanism 150 without being expanded. The refrigerant passing through the outdoor expansion mechanism 150 may flow into the liquid pipe 33 along the liquid tube 331 and the liquid connection tube 332. The refrigerant flowing into the liquid pipe 33 may be expanded while passing through the indoor liquid tube 333 to flow into each of the indoor expansion mechanisms 213, 223, 233, and 243. The expanded refrigerant may be evaporated while passing through each of the indoor heat exchangers 211, 221, 231, and 241. The evaporated refrigerant may flow into the low pressure gas pipe 31 along the indoor gas tube 313. The refrigerant flowing into the low pressure gas pipe 31 may flow into the second connection tube 134 along the low pressure connection tube 312 and the low pressure gas tube 311. Then, the refrigerant may be introduced into the accumulator 135. A gaseous portion of the refrigerant introduced into the accumulator 135 may be introduced into the compression device 110.

FIG. 4 is a flowchart of a method for controlling a multi-type air conditioner according to an embodiment. FIGS. 5 to 8 are block diagram illustrating successive defrosting operations of a plurality of outdoor devices. FIGS. 9 and 10 are circuit diagrams of a refrigerant flow when a specific outdoor device performs a defrosting operation, FIG. 9 illustrating a refrigerant flow when a fourth outdoor device performs a defrosting operation, and FIG. 10 illustrating a refrigerant flow when a first outdoor device performs a defrosting operation.

Referring to FIGS. 4 to 10, the multi-type air conditioner, such as the multi-type air conditioner of FIG. 1, may perform a heating operation according to a heating operation command, in step S1. In step S2, a controller may determine that a defrosting operation condition or conditions is satisfied during the heating operation of the multi-type air conditioner.

According to this embodiment, whether the defrosting operation conditions are satisfied may be determined, for example, by comparing an outlet tube temperature of the outdoor heat exchanger to an outdoor temperature. Because the plurality of outdoor devices are operated at the same time, time points at which the defrosting operation conditions are satisfied in the plurality of outdoor devices may be similar to each other. However, the time points at which the defrosting operation conditions are satisfied in the outdoor devices may be different from each other. In a case in which the defrosting operation conditions are satisfied in the multi-type air conditioner, the defrosting operation conditions may be satisfied in all of the outdoor devices or in a certain number of the outdoor devices.

According to this embodiment, whether the defrosting operation conditions are satisfied may be determined through various methods including the above-described method. That is, the present disclosure is not limited to any particular method for determining whether the defrosting operation conditions are satisfied.

In the result determined in step S2, when the defrosting operation conditions are satisfied, the multi-type air conditioner may be operated in a defrosting operation mode. More specifically, in step S3, the plurality of outdoor devices may be successively operated in the defrosting operation mode. That is, one outdoor device may perform the defrosting operation, while the remaining outdoor devices may perform the heating operation. When one outdoor device completely performs the defrosting operation, the next outdoor device may perform the defrosting operation.

In this embodiment, for example, an order of the outdoor devices performing the defrosting operation may be decided based on a capacity (a heat exchange capacitor) of each of the outdoor devices. That is, in a case in which all or a portion of the outdoor devices have capacities different from each other, the outdoor device having a relatively small capacity may perform the defrosting operation first. If all or a portion of the outdoor devices have the same capacity, the outdoor devices may perform the defrosting operation according to a preset order. That is, during manufacture, an order of the outdoor devices performing the defrosting operation may be set, and this order stored in a memory (not shown). When the defrosting operation conditions are satisfied, the defrosting operation may be performed according to the preset order. A change of the previously decided order may be impossible or possible.

As another example, the order of the outdoor devices performing the deforesting operation may be decided whenever the defrosting operation conditions are satisfied. For example, the outdoor devices may perform the defrosting operation in an order based on a time point (i.e. from the fastest time point) at which the defrosting operation conditions are satisfied for each outdoor device.

In this embodiment, for example, the outdoor devices may perform the defrosting operation in an order of a fourth indoor device, a third indoor device, a second indoor device, and a first indoor device.

Referring to FIGS. 5 to 9, when the fourth outdoor device 14 performs the defrosting operation, the outdoor heat exchanger 220 of the fourth outdoor device 14 may switched into a condenser state by switching the refrigerant flow through the valve of the fourth outdoor device 14. That is, as shown in FIG. 5, the plurality of heat exchanger parts of the fourth outdoor device 14 may be switched into the condenser state. Each of the outdoor heat exchanger 130, 200, and 210 of the first to third indoor devices 11, 12, and 13 may be maintained in an evaporator state, and each of the indoor heat exchangers 211, 221, 231, and 241 of each of the indoor devices 21, 22, 23, and 24 may be maintained in the condenser state.

Thus, the high-temperature, high-pressure refrigerant discharged from the compression device of the fourth outdoor device 14 may flow into the outdoor heat exchanger 220 via the valve. When the high-temperature, high-pressure refrigerant passes through the outdoor heat exchanger 220, frost on the outdoor heat exchanger 220 may be removed.

The refrigerant passing through the outdoor heat exchanger 220 of the fourth outdoor device 14 may flow along the liquid tube 331 of the fourth outdoor device 14, and then, the refrigerant together with the refrigerant discharged from the liquid pipe 33 may be introduced into the liquid tube 331 of the first outdoor device 11. The second valve 326 disposed in the high pressure gas tube 321 of the fourth outdoor device 14 may be closed during the defrosting operation of the fourth outdoor device 14. An operation of the fan motor assembly 140 disposed in the fourth outdoor device 14 may be stopped during the defrosting operation of the fourth outdoor device 14. Also, an opening degree of the outdoor expansion valve 151, 152 of the fourth outdoor device 14 may be greater than that of the previous state (i.e., an opening degree of the outdoor expansion valve when the outdoor heat exchanger of the fourth outdoor device serves as an evaporator).

Also, a portion of the refrigerant evaporated while passing through the outdoor heat exchanger in the first to third outdoor devices 11, 12, and 13 may flow into the accumulator 135 of the first to third outdoor devices 11, 12, and 13. The other portion of the refrigerant may flow into the accumulator 135 of the fourth outdoor device 14 along the low pressure gas tube 311. When the defrosting operation of the fourth outdoor device 14 is completed, the outdoor heat exchanger 220 of the fourth outdoor device 14 may be switched into the evaporator state by switching the refrigerant flow through the valve.

Thus, as shown in FIG. 6, the third outdoor device 13 may perform the defrosting operation. When the third outdoor device 13 performs the defrosting operation, the outdoor heat exchanger 210 of the third outdoor device 13 may serve as the condenser, and the outdoor heat exchangers of the remaining outdoor devices may serve as the evaporators. When the defrosting operation of the third outdoor device 13 is finished, the second outdoor device 12 may perform the defrosting operation, as shown in FIG. 7. When the second outdoor device 12 performs the defrosting operation, the outdoor heat exchanger 210 of the second outdoor device 12 may serve as the condenser, and the outdoor heat exchangers of the remaining outdoor devices may serve as the evaporators. When the defrosting operation of the second outdoor device 12 is finished, the first outdoor device 11 may perform the defrosting operation.

Referring to FIG. 10, when the first outdoor device 11 performs the defrosting operation, the outdoor heat exchanger 130 of the first outdoor device 11 may be switched to the condenser state by switching the refrigerant flow through the valve. Each of the outdoor heat exchangers of the second to fourth outdoor devices 12, 13, and 14 may be maintained in the evaporator state, and each of the indoor heat exchangers 211, 221, 231, and 241 of the each of the indoor devices 21, 22, 23, and 24 may be maintained in the condenser state.

Thus, the high-temperature, high-pressure refrigerant discharged from the compression device of the first outdoor device 11 may flow into the outdoor heat exchanger 130 via the valve. When the high-temperature, high-pressure refrigerant passes through the outdoor heat exchanger 130, frost on the outdoor heat exchanger 130 may be removed.

The refrigerant passing through the outdoor heat exchanger 130 of the first outdoor device 11 may flow along the liquid tube 331 of the first outdoor device 11, and then, the refrigerant together with the refrigerant discharged from the liquid pipe 33 may be introduced into the liquid tubes 331 of the second to fourth outdoor devices 12, 13, and 14. The second valve 325 disposed in the high pressure gas tube 321 of the first outdoor device 11 may be closed during the defrosting operation of the first outdoor device 11. An operation of the fan motor assembly 140 disposed in the first outdoor device 11 may be stopped during the defrosting operation of the first outdoor device 11. Also, an opening degree of the outdoor expansion valve 151, 152 of the first outdoor device 11 may be greater than that of the previous state (i.e., an opening degree of the outdoor expansion valve when the outdoor heat exchanger of the first outdoor device serves as an evaporator).

When the defrosting operation of the first outdoor device 11 is completed, the defrosting operation of all of the outdoor devices may be determined to be completed, in step S4. Then, the defrosting process may return to step S1, and each of the outdoor heat exchangers 130, 200, 210, and 220 of each of the outdoor devices 11, 12, 13, and 14 may be switched to the evaporator state.

According to embodiments disclosed herein, because the indoor device may perform a heating operation during a defrosting operation of the air conditioner, the indoor space may be continuously heated to maintain a comfortable indoor space. Also, because the outdoor heat exchangers do not perform the defrosting operation at the same time, but rather, successively perform the defrosting operation, deterioration of heating performance may be minimized. Further, because the frost on all of the outdoor heat exchangers of each of the outdoor devices may be removed, frost may be preventing from remaining on a portion of the outdoor heat exchangers.

Embodiments disclosed herein provide a multi-type air conditioner and a method of controlling a multi-type air conditioner in which a defrosting operation may be performed in a state in which deterioration of heating performance may be minimized.

A multi-type air conditioner according to embodiments disclosed herein may include a plurality of indoor units or devices, each including an indoor heat exchanger; and a plurality of outdoor units or devices connected to the plurality of indoor units, each including an outdoor heat exchanger, wherein, when a defrosting operation condition is satisfied during a heating operation, the plurality of outdoor units may successively perform a defrosting operation.

A multi-type air conditioner according to embodiments disclosed herein may include a plurality of indoor units or devices, each including an indoor heat exchanger; and a plurality of outdoor units or devices connected to the plurality of indoor units, each including an outdoor heat exchanger, wherein, when a defrosting operation condition is satisfied during a heating operation, the outdoor heat exchanger of one outdoor unit of the plurality of outdoor units may be switched into a condenser state to perform a defrosting operation.

A method of controlling a multi-type air conditioner including a plurality of indoor units or devices and a plurality of outdoor units or devices according to embodiments disclosed herein may include performing a heating operation in the plurality of outdoor units; determining whether a defrosting operation condition is satisfied during the heating operation of the plurality of outdoor units; and successively performing a defrosting operation in the plurality of outdoor units when the defrosting operation condition is satisfied.

Even though all the elements of embodiments may be coupled into one or operated in a combined state, the present disclosure is not limited to such an embodiment. That is, all the elements may be selectively combined with each other without departing from the scope of the invention. Further, when it is described that one comprises (or includes or has) some elements, it should be understood that it may comprise (or include or has) only those elements, or it may comprise (or include or have) other elements as well as those elements if there is no specific limitation. Unless otherwise specifically defined herein, all terms including technical or scientific terms are to be given meanings understood by those skilled in the art. Like terms defined in dictionaries, generally used terms needs to be construed as meaning used in technical contexts and are not construed as ideal or excessively formal meanings unless otherwise clearly defined herein.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the embodiments should be considered in descriptive sense only and not for purposes of limitation, and also the technical scope of the invention is not limited to the embodiments. Further, is defined not by the detailed description of the invention but by the appended claims, and all differences within the scope will be construed as being comprised in the present disclosure.

Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. 

1. A multi-type air conditioner, comprising: a plurality of indoor devices, each comprising an indoor heat exchanger; and a plurality of outdoor devices connected to the plurality of indoor devices, each comprising an outdoor heat exchanger, wherein, when a defrosting operation condition is satisfied during a heating operation, the plurality of outdoor devices successively perform a defrosting operation.
 2. The multi-type air conditioner according to claim 1, wherein each of the plurality of outdoor devices comprises a valve, wherein during the heating operation, the outdoor heat exchanger of each of the plurality of outdoor devices not currently performing the defrosting operation serves as an evaporator by switching a refrigerant flow through the valve, and wherein the outdoor heat exchanger in which the defrosting operation is currently being performed serves as a condenser by switching the refrigerant flow through the corresponding valve.
 3. The multi-type air conditioner according to claim 2, wherein the valve comprises a four-way valve.
 4. The multi-type air conditioner according to claim 3, wherein each outdoor heat exchanger is divided into a plurality of heat exchanger parts through which a refrigerant separately flows, and wherein when a specific outdoor device of the plurality of outdoor devices performs the defrosting operation, frost on all of the heat exchanger parts of the specific outdoor device is removed.
 5. The multi-type air conditioner according to claim 4, wherein each of the plurality of outdoor devices comprises a plurality of four-way valves, and wherein the number of four-way valves is equal to that of heat exchanger parts.
 6. The multi-type air conditioner according to claim 1, wherein an order of the plurality of outdoor devices performing the defrosting operation is based on a heat exchange capacity of the outdoor heat exchanger of each of the outdoor devices.
 7. The multi-type air conditioner according to claim 6, wherein the outdoor device comprising a outdoor heat exchanger having a relatively small capacity performs the defrosting operation first.
 8. The multi-type air conditioner according to claim 1, wherein an order of the plurality of outdoor devices performing the defrosting operation is preset.
 9. The multi-type air conditioner according to claim 8, further comprising a memory in which the preset order is stored.
 10. The multi-type air conditioner according to claim 1, wherein an order of the plurality of outdoor devices performing the defrosting operation is determined whenever the defrosting operation condition is satisfied.
 11. The multi-type air conditioner according to claim 1, wherein, during the defrosting operation, an operation of an outdoor fan disposed in the outdoor device performing the defrosting operation is stopped.
 12. A multi type air-conditioner, comprising: a plurality of indoor devices, each comprising an indoor heat exchanger; and a plurality of outdoor devices connected to the plurality of indoor devices, each comprising an outdoor heat exchanger, wherein, when a defrosting operation condition is satisfied during a heating operation, the outdoor heat exchanger of one of the plurality of outdoor device is switched into a condenser state to perform a defrosting operation.
 13. The multi-type air conditioner according to claim 12, wherein, when the outdoor heat exchanger of the one of the plurality of outdoor devices completely performs the defrosting operation, the outdoor heat exchanger of another outdoor device is switched into the condenser state to perform the defrosting operation.
 14. The multi-type air conditioner according to claim 13, wherein an order of the plurality of outdoor devices performing the defrosting operation is based on a heat exchange capacity of the outdoor heat exchanger of each of the plurality of outdoor devices.
 15. The multi-type air conditioner according to claim 13, wherein an order of the plurality of outdoor devices performing the defrosting operation is preset.
 16. The multi-type air conditioner according to claim 15, further comprising a memory in which the preset order is stored.
 17. The multi-type air conditioner according to claim 13, wherein an order of the plurality of outdoor devices performing the defrosting operation is determined whenever the defrosting operation condition is satisfied.
 18. The multi-type air conditioner according to claim 12, wherein each of the outdoor heat exchangers of the plurality of outdoor devices is divided into a plurality of heat exchanger parts through which a refrigerant independently flows, and wherein when a specific outdoor device performs the defrosting operation, frost on all of the plurality of heat exchanger parts is removed.
 19. The multi-type air conditioner according to claim 12, wherein, when a specific outdoor device performs the defrosting operation, an operation of an outdoor fan disposed in the outdoor device performing the defrosting operation is stopped.
 20. A method of controlling a multi-type air conditioner comprising a plurality of indoor devices and a plurality of outdoor devices, the method comprising: performing a heating operation in the plurality of outdoor devices; determining whether a defrosting operation condition is satisfied during the heating operation of the plurality of outdoor devices; and successively performing a defrosting operation in the plurality of outdoor devices when the defrosting operation condition is satisfied.
 21. The method according to claim 20, wherein, when a specific outdoor device performs the defrosting operation, an outdoor heat exchanger of the respective outdoor device serves as a condenser by switching a refrigerant flow through a four-way valve.
 22. The method according to claim 20, wherein the successively performing of the defrosting operation comprises performing the defrosting operation in another outdoor device after a specific outdoor device completely performs the defrosting operation.
 23. The method according to claim 20, wherein, when a specific outdoor device performs the defrosting operation, an operation of a corresponding outdoor fan of the specific outdoor device is stopped.
 24. The method according to claim 20, wherein an order of the plurality of outdoor devices performing the defrosting operation is based on a heat exchange capacity of an outdoor heat exchanger of each of the plurality of outdoor devices.
 25. The method according to claim 20, wherein an order of the plurality of outdoor devices performing the defrosting operation is preset.
 26. The method according to claim 20, wherein an order of the plurality of outdoor devices performing the defrosting operation is determined whenever the defrosting operation condition is satisfied. 